So is there a way to tell perl not to copy a specific variable while creating new threads ?

I don't have Net::AMQP::RabbitMQ, so this is untested, but if your description is accurate, it ought to work.

Just re-structure your code slightly:

#!/usr/bin/perl
use Cwd qw/realpath/;
use File::Basename qw/dirname/;
use lib 'lib';
use threads;
use threads::shared;
use initial;

my @threads = ();
my $run :shared = 1;

sub proc1 {
    while($run){
        sleep(1);
        print "I am child thread 1 \n"
    }
}

sub proc2 {
    while($run){
       sleep(1);
       print "I am child thread 2 \n";
    }
}

threads->create(\&proc1);
threads->create(\&proc2);

my $init = load initial($name);

$SIG{'TERM'} = sub {
    $run = 0;
};

while($run){
    sleep(1);
    print "I am main thread\n";
}

$_->join() for threads->list();
[download]

In general, it is better to start your threads before you create/allocate anything that is only used by your main thread.

See threads: spawn early to avoid the crush. for more details.